SLC6A4 rs1042173: Understanding Your Serotonin Transporter Variant
The rs1042173 variant is a single nucleotide polymorphism located in the 3' untranslated region (UTR) of the SLC6A4 gene. It is primarily studied for its potential role in modulating serotonin transporter expression and its association with emotional stress susceptibility and treatment responses in certain conditions.
What each genotype means
Typical Serotonin Transporter Expression
You carry two copies of the C allele in the 3' untranslated region of the SLC6A4 gene. Research suggests this baseline genotype shows typical mRNA regulation and average susceptibility to stress-related emotional symptoms. However, scientific evidence linking this individual variant to clinical psychological outcomes remains limited and mixed.
Carried by approximately 30% to 40% of individuals across global populations, being slightly more prevalent in East Asian ancestries.
Intermediate Environmental Stress Sensitivity
You carry one copy of the T allele and one copy of the C allele in the SLC6A4 gene. Preliminary studies suggest the T allele may subtly alter mRNA stability and contribute to stress susceptibility when interacting with significant life adversity, often evaluated within multi-gene serotonergic scores. Because clinical evidence for this single marker is limited and non-diagnostic, it does not determine your emotional well-being.
Carried by roughly 45% to 50% of people across most worldwide populations, representing the most common genotype.
Altered Serotonin Transporter Regulation
You carry two copies of the T allele in the regulatory region of the SLC6A4 gene. Some research models associate this genotype with altered serotonin transporter expression and heightened vulnerability to interpersonal stress or depressive symptoms following environmental trauma. Findings are exploratory with limited standalone effect sizes, so this genotype does not indicate or diagnose any mental health condition.
Carried by roughly 12% to 20% of individuals globally, depending on ancestry.
What is rs1042173?
The rs1042173 variant is a specific genetic change, or single nucleotide polymorphism (SNP), found within the SLC6A4 gene. This gene is located on chromosome 17 and is responsible for encoding the serotonin transporter protein. The rs1042173 variant is situated in the 3' untranslated region (3' UTR) of the gene. This region does not code for the protein itself but plays a critical role in regulating the stability and expression levels of the messenger RNA (mRNA) produced by the gene. By influencing how much mRNA is available to be translated into functional transporter proteins, variants in this region may theoretically alter the density of serotonin transporters in the brain. Researchers study this site to understand how subtle differences in genetic sequence might contribute to individual variations in neurobiology and behavioral traits.
The Role of the SLC6A4 Gene
The SLC6A4 gene encodes the serotonin transporter (SERT), a vital protein that regulates the amount of serotonin available in the synaptic cleft, the space between neurons. Serotonin is a neurotransmitter involved in mood regulation, sleep, appetite, and cognitive function. By transporting serotonin from the synaptic cleft back into the presynaptic neuron, the SERT protein effectively terminates the signal, maintaining a balance of neurotransmitter activity. Because of its central role in serotonin signaling, the SLC6A4 gene is a primary target for many psychiatric medications, including selective serotonin reuptake inhibitors (SSRIs). Variations in this gene, including those in regulatory regions like the 3' UTR, are frequently investigated to see if they influence how individuals process serotonin or respond to environmental stressors and pharmacological interventions.
Research and Evidence Strength
Scientific evidence linking rs1042173 to specific health outcomes is currently considered limited. While some studies have explored its role in emotional stress susceptibility and its interaction with environmental trauma, results have been inconsistent across different populations. Some research has suggested that specific genotypes may influence treatment responses in individuals with alcohol use disorders, particularly when considering the efficacy of certain medications like ondansetron. However, these findings often come from small-scale studies or exploratory analyses. It is important to note that psychiatric and behavioral traits are complex and influenced by a vast array of genetic, environmental, and lifestyle factors. Consequently, a single SNP like rs1042173 is unlikely to be a sole determinant of any complex condition. Much of the existing literature remains exploratory, and more large-scale, replicated studies are required to confirm the clinical significance of this variant.
What You Can Do With This Information
Genetic information regarding variants like rs1042173 is primarily for educational purposes and should not be used to make medical decisions. Because the evidence for this variant is limited and mixed, it cannot be used to predict your risk for specific psychiatric conditions or to determine how you will respond to medications. If you are concerned about your mental health or are considering changes to your treatment plan, it is essential to consult with a qualified healthcare provider or a psychiatrist. They can evaluate your symptoms, medical history, and other relevant factors to provide appropriate care. Never initiate, stop, or change the dosage of any medication based on genetic test results without direct guidance from your clinician or pharmacist. Understanding your genetic makeup can be an interesting part of your health journey, but it should always be interpreted within the context of professional medical advice.
How common is this variant?
The minor allele (T) of rs1042173 has a global frequency of approximately 0.35 to 0.45, though this can vary significantly depending on ancestral background.
Frequently asked questions
Can this variant predict if I will get depression?
No, this variant cannot predict the development of depression. Depression is a complex condition influenced by many genes and environmental factors, and the evidence linking rs1042173 to depression is not strong enough for clinical prediction.
Should I change my medication based on this result?
You should never change your medication based on genetic test results without consulting your doctor. Always discuss any concerns about your treatment or potential side effects with your clinician or pharmacist.
Is rs1042173 the same as the 5-HTTLPR polymorphism?
No, they are different. 5-HTTLPR is a well-known variable number tandem repeat (VNTR) in the promoter region of the SLC6A4 gene, whereas rs1042173 is a single nucleotide polymorphism in the 3' UTR.
Where can I find more information about my specific genotype?
You can look up your specific SNP on databases like dbSNP or ClinVar for technical details. However, for health-related questions, always prioritize information from your healthcare provider or reputable medical organizations.
Sources & further reading
Educational information only, last refreshed 10/10/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Current evidence-based reviews conclude that SLC6A4 variants do not currently support actionable clinical antidepressant guidance.
This variant (often studied alongside 5-HTTLPR) is located in the promoter region of the serotonin transporter gene; however, clinical evidence for its utility in predicting antidepressant response remains inconsistent and non-actionable.
A functional A/G variant within the 5-HTTLPR locus of the serotonin transporter gene. While historically hypothesized to modulate stress reactivity, large-scale replication studies and meta-analyses have largely failed to confirm consistent associations with psychiatric phenotypes or treatment response.